J/MNRAS/351/1071 POINT-AGAPE Survey. M31 variables (An+, 2004)
The POINT-AGAPE Survey - I. The variable stars in M31.
An J.H., Evans N.W., Hewett P., Baillon P., Novati S.C., Carr B.J.,
Creze M., Giraud-heraud Y., Gould A., Jetzer P., Kaplan J., Kerins E.,
Paulin-henriksson S., Smartt S.J., Stalin C.S., Tsapras Y.
<Mon. Not. R. Astron. Soc., 351, 1071-1098 (2004)>
=2004MNRAS.351.1071A 2004MNRAS.351.1071A
ADC_Keywords: Galaxies, photometry ; Stars, variable
Keywords: gravitational lensing - Cepheids - stars: variables: others -
galaxies: individual: M31 - dark matter
Abstract:
For the purposes of identifying microlensing events, the POINT-AGAPE
collaboration has been monitoring the Andromeda galaxy (M31) for three
seasons (1999-2001) with the Wide Field Camera on the Isaac Newton
Telescope. In each season, data are taken for one hour per night for
roughly 60 nights during the six months that M31 is visible. The two
33x33arcmin2 fields of view straddle the central bulge, northwards
and southwards. We have calculated the locations, periods and
brightness of 35 414 variable stars in M31 as a by-product of the
microlensing search. The variables are classified according to their
period and brightness. Rough correspondences with classical types of
variable star (such as Population I and II Cepheids, Miras and
semiregular long-period variables) are established. The spatial
distribution of Population I Cepheids is clearly associated with the
spiral arms, while the central concentration of the Miras and
long-period variables varies noticeably, the brighter and the shorter
period Miras being much more centrally concentrated.
Description:
Observations of M31 were obtained using the Wide Field Camera (WFC)
mounted on the 2.5-m Isaac Newton Telescope (INT) located at La Palma,
the Canary Islands, Spain, over three observing seasons, from 1999
August to 2002 January. Three broad-band filters, g, r and i, were
employed.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table23.dat 65 37657 Variables in Group 1-4 and 5
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See also:
J/A+A/421/509 : AGAPE catalogue of M31 variables (Ansari+, 2004)
Byte-by-byte Description of file: table23.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Seq POINT-AGAPE Catalogue identifier
7 A1 --- Field [1-8] Field & CCD
(= CCD No. + 4*[Field No. - 1])
9- 10 I2 h RAh Right ascension (J2000)
11 A1 --- --- [:]
12- 13 I2 min RAm Right ascension (J2000)
14 A1 --- --- [:]
15- 20 F6.3 s RAs Right ascension (J2000)
21 A1 --- DE- Declination sign (J2000)
22- 23 I2 deg DEd Declination (J2000)
24 A1 --- --- [:]
25- 26 I2 arcmin DEm Declination (J2000)
27 A1 --- --- [:]
28- 33 F6.3 arcsec DEs Declination (J2000)
35- 39 F5.2 mag rDf Amplitude in broad-band r filter (G1)
41- 45 F5.2 mag gDf ?=00.00 Amplitude in broad-band g filter (G1)
47- 51 F5.2 mag iDf ?=00.00 Amplitude in broad-band i filter (G1)
53- 57 F5.3 [d] logP log10 of Period
59- 65 F7.3 --- logFAP log10 of false alarm probability from
Lomb's periodogram
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Global notes:
Note (G1): The flux variation Deltaf between minimum and maximum
expressed in ADU/s is converted into pseuso-magnitude by
r(Deltaf)=r0-2.5*log10(Deltaf).
g(Deltaf) and i(Deltaf) set to zero if no variability detected.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 06-Sep-2004